Prevalence of filariasis among prospective blood donors at Ladoke Akintola University Teaching Hospital, Osogbo, Nigeria

Abstract

It has been stated that high prevalence of microfilaria in Africa has compounded the problem of blood shortage in our blood banks as prospective blood donors positive for microfilaria are automatically excluded from donation. This fact, together with changing population demographics, increased travels with respect to rural urban migration and the problems of commercial blood donors has made it necessary to determine the prevalence of filarial infection among blood donors in our institution. A total of 491 subjects aged 18 years and above and voluntarily consenting to donate blood at the blood bank of the Ladoke Akintola University Teaching Hospital, Osogbo, Nigeria between April and June 2005 were screened for microfilaria. Five milliliters of blood was collected from each subject. The modified thick smear technique described by Denham, and Giemsa and Haematoxylin stains were used to detect microfilaria in the blood. Of the 491 prospective blood donors (402 males, 89 females, M:F ratio 4.5:1, age range 18-62 years) screened, the age group 21-30 years and 31-40 years constituted 39.3% and 28.3% respectively. Five (1.01%) were positive for microfilaria; 3 (60%) had Mansonella perstans, 1 (20%) had Onchocerca volvulus while 1 (20%) had Loa loa. All the 5 donors were male aged 23, 25, 31, 50 and 55 years and were asymptomatic. The average parasite density of the donors was 1.4 microfilaria/20 µL of blood. Because of the possibility of allergic reactions from transfused microfilariae, routine screening for microfilariae should be incorporated into transfusion policy in our hospitals. However, in view of the generally low apathy to voluntary blood donation in Nigeria, it may not be justified to exclude potential donor positive for microfilaria. Instituting prompt antifilarial treatment for patients receiving such blood may be a credible alternative

Keywords: Prevalence, Filariasis, Blood donors, Osogbo

Nigerian Journal of Health and Biomedical Sciences Vol. 5 (2) 2006: 71-73